Researchers find building blocks of life on asteroids – what that means

Ryugu is a diamond-shaped asteroid with a diameter of 900 meters orbiting the sun. In 2018, a Japanese probe landed on the celestial body and collected rock samples.

In 2020, the researchers started the analysis. They found that there were building blocks of life on the asteroid. The results were published by the Japanese research team in the journal Nature on Tuesday.

When analyzing the asteroid dust, the researchers were able to detect uracil and vitamin B3. Uracil is a building block of the carrier RNA of genetic material and vitamin B3 is an important compound for the metabolism of living organisms.

What does that mean? The finding supports the long-standing theory that life on Earth received useful support from space. Meteorites would have enriched the young Earth with prebiotic organics and thus promoted the emergence of life.

The theory has been around for a long time because researchers have already found all of the building blocks of RNA on meteorites. The cosmic rock that remains after the asteroid enters Earth’s atmosphere and lands on Earth is called a meteorite. Excellent research material for scientists. However, subject to: Because meteorites can be contaminated from their landing on Earth.

The study’s lead author, Yasuhiro Oba, an associate professor at Hokkaido University in Japan, explains:

In other words, the chemicals found on meteorites might as well have come from Earth itself rather than from outer space, due to pollution. There was only one way for the researchers to remove this uncertainty – and a long one: Collecting rock samples from an asteroid in space.

They have done that successfully. With Ryugu’s asteroid dust subsequently analyzed, the clues are that that the building blocks of life were actually formed in space. Only billions of years ago they would have been brought to Earth by meteorites.

Obama explains:

Do these building blocks of life indicate that extraterrestrial life might exist? Oba cannot confirm this. However, he does not deny it either:

Astronomers focus on asteroids for a reason: Of all the matter floating in our solar system, asteroids are considered to be the most pristine material still in existence. Unlike planets, they have remained largely undisturbed since the formation of the solar system 4.5 billion years ago. Their composition can therefore provide valuable information about the formation of our solar system.

Researchers believe that organic molecules formed in the cold cloud of gas and dust that formed our solar system. These substances would have been found on floating bodies.

According to the researchers, Ryugu is a fragment of an older body that formed in the early days of the solar system and was later destroyed by a collision with another celestial body. According to current knowledge, this original body was initially heated by radioactivity, which allowed liquid water to form. This led to chemical reactions with the already existing organic molecules, resulting in the formation of larger macromolecules.

As the analyzes showed, the temperature during these processes was around 40 degrees for several million years. Then Ryugu’s original body slowly cooled and froze – a stroke of luck for the researchers. This left the organic molecules virtually unchanged and so the researchers were able to reconstruct the history of the asteroid’s formation.

And how exactly did the mission to the asteroid Ryugu go? The Hayabusa 2 probe began its journey precisely on December 3, 2014 at 04:22:04 from the Tanegashima Space Center in Japan. After a four-year journey, she reached the asteroid 3000 million kilometers away, where she had to overcome a number of challenges.

For example, she had to drop the German passenger – the MASCOT lander made in Germany – onto the surface of the asteroid. Not an easy task due to the low gravity: this is only one 60,000th of the asteroid’s gravity. As an illustration: An elephant on Ryugu would weigh about as much as a bar of chocolate on Earth. For this, the mobile asteroid explorer MASCOT had to land very carefully, otherwise it would have bounced off the surface and disappeared into the depths of space.

The landing was successful, after which the shoebox-sized device began to survey the asteroid’s surface. It had 17 hours to do this, then the batteries gave up as planned.

A few months later, Hayabusa 2 shot a copper projectile into the asteroid’s surface, creating an impact crater 10 meters wide. This allowed the probe to reach rock samples further below the surface. This mission was also successful and so Hayabusa 2 left the asteroid Ryugu a short time later with two rock samples in its luggage – one from the surface, one from the crater.

On December 6, 2020, the probe flew past Earth and dropped a landing capsule containing the rock samples. This shot fiery through the Earth’s atmosphere before landing gently in the South Australian outback thanks to a parachute, where it was eventually captured. The samples have been examined by the Japanese space agency since 2020 and by NASA and other researchers since last year.

And what about Hayabusa 2? The Japanese probe will not return to Earth for a long time, because after dropping the landing capsule it went directly to the next mission.

Their target is the near-Earth small asteroid “1998KY26” with a diameter of only 30 meters. However, the astronomers will have to wait a little longer for the probe to arrive there: The arrival of the probe is dated July 2031.